The present invention relates to a fuse for an electric firing projectile, comprising a circuit with an electric primer, a generator operating by inertia to supply under the accleration effect of the firing of the shot a charge to a capacitor intended to provide the energy for firing the electric primer by way of a firing contactor, the generator comprising a mobile magnetic core which is part of a magnetic circuit associated with a winding, the core being intended to move relative to the circuit to induce in the winding a current for charging the capacitor, the displacement of the core being prevented before the firing of the shot by a security member intended to be deformed when the generator is in operation.